1. Field of the Invention
The present invention relates to an image forming apparatus including an image reading portion that reads image information from a recording body, such as an original or an opened book, and an image recording portion that records an image on a sheet.
2. Related Background Art
Various image forming apparatuses have conventionally been used, examples of which include a copying machine, a facsimile, a printer, and a composite machine integrating functions of these apparatuses. Also, in general, many image forming apparatuses have a construction in which an image reading portion having an original stand that can be upwardly opened is disposed in an upper portion of an apparatus main body to thereby improve user's operability in placing an original and an image recording portion is disposed in a lower portion of the apparatus main body.
Also, many old-type image forming apparatuses adopt a construction in which a sheet on which an image has been formed in an image recording portion is delivered onto a tray provided on a side surface of an apparatus main body. If the tray protrudes from the side surface, however, the installation space for the apparatus main body needs to be increased by an area corresponding to the projection area of the tray. In view of this problem, image forming apparatuses with reduced installation spaces have come into general use. Such image forming apparatuses have a construction in which an image reading portion is disposed above an image recording portion, and a sheet on which an image has been formed is delivered into a space between the image recording portion and the image reading portion, thereby preventing protrusion of the sheet to the outside from a side of an apparatus main body. Also, image forming apparatuses have been developed which have a construction which enables improvement in ease of taking a sheet out, visibility of the sheet, and the like as well as miniaturization of the apparatus. Examples of such image forming apparatuses will be described below.
An image forming apparatus 101 of a first conventional example shown in FIG. 12 is an image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 08-339106. This image forming apparatus 101 includes an image recording portion 112 and an image reading portion 114, with the image recording portion 112 delivering a sheet on which an image has been formed, to a delivery tray 111 provided above the image recording portion 112 and the image reading portion 114 being disposed above the delivery tray 111 and being held by a supporting member 113. Also, in the image forming apparatus 101, a center position SC of the image reading portion 114 is displaced backward relative to a sheet delivery center position HC of the image recording portion 112. With this construction, an operation portion 115 is prevented from protruding to the outside on the front side (right side in the drawing) and thus visibility of the sheet delivered onto the delivery tray 111 and ease of taking out of the delivered sheet are improved.
An image forming apparatus 102 of a second conventional example shown in FIG. 13 is an image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 2000-295411. This image forming apparatus 102 includes an image recording portion 122 and an image reading portion 124. The image recording portion 122 delivers a sheet on which an image has been formed, onto a delivery tray 121 provided above the image recording portion 122 and the image reading portion 124 is disposed above the delivery tray 121. In this image forming apparatus 102, the lower surface of the image reading portion 124 on the front side is situated at a height higher than the rear-side height thereof. With this construction, the sheet taking-out space B is enlarged on the front side and ease of taking out of a sheet is thus realized without increasing the height of the image reading portion 124 more than necessary. Also, provided on the front side of the image reading portion 124 is an operation portion 125 with which the whole of the image forming apparatus 102 is operated.
In the case of the image forming apparatus 101 of the first conventional example, however, in order to improve visibility of the delivered sheet, a sheet delivery space A between the image recording portion 112 and the image reading portion 114 and between the image recording portion 112 and the operation portion 115 is required to have a height which allows the sheet to be taken out therefrom. Consequently, the heights of the image reading portion 114 and the operation portion 115 are increased, which leads to a problem that ease of setting of an original and ease of input of commands using the operation portion 115 are impaired. Also, the supporting member 113 provided below the operation portion 115 becomes an obstacle when a user takes the sheet out, which means that it is difficult for the user to take the sheet out. Further, there is a danger that the sheet may contact the supporting member 113 and be damaged.
Like in the first conventional example, in the case of the image forming apparatus 102 of the second conventional example, in order to improve visibility of the delivered sheet, the sheet delivery space B between the image recording portion 122 and the image reading portion 124 and between the image recording portion 122 and the operation portion 125 is required to have a considerable height and therefore the positions of the image reading portion 124 and the operation portion 125 are raised, which results in a problem that it becomes difficult to set an original and to input commands using the operation portion 125.
Also, the image forming apparatuses of the first and second conventional examples do not address the following points: the construction for electrically connecting a command input circuit board, which is required in association with the operation portion, to a main body control circuit board; the construction in which a consideration is given to electric noise with respect to the arrangement and connection of the circuit boards; the arrangement and construction of motors for driving the image reading portion and the image recording portion and a fan motor for cooling the image recording portion; the construction for preventing the adverse effect of the electric noise generated from these motors on the circuit boards, and the like.